Calorimetric investigation of phase transitions in the layered antiferromagnetic molecule-based material {N(n-C5H11)4[MnIIFeIII(ox)3]}∞(ox=oxalato)

Calorimetric Investigation of Phase Transitions Occurring in Molecule-Based Magnets

“…Recently, Bhattacharjee et al measured heat capacities of analogous assembled-metal complexes NBu 4 [Fe II Fe III (ox) 3 ], − NBu 4 [Zn II Fe III (ox) 3 ], , NPr 4 [Fe II Fe III (ox) 3 ] (Pr = n -C 3 H 7 ), NBu 4 [Co II Fe III (ox) 3 ], and NPe 4 [Mn II Fe III (ox) 3 ] (Pe = n -C 5 H 11 ) and showed that these compounds exhibit similar behavioral characteristics of 2D structures. Antorrena et al also reported that the magnetic heat capacities of PPh 4 [MnCr(ox) 3 ] and PPh 4 [Fe II Cr III (ox) 3 ] indicate 2D characters.…”

“…The coincidence of the dimensionality derived from the HT series expansion method with the results of X-ray structural analysis would guarantee the usefulness of the calorimetry. Recently, Bhattacharjee et al measured heat capacities of analogous assembled-metal complexes NBu 4 [Fe II -Fe III (ox) 3 ], [189][190][191] NBu 4 [Zn II Fe III (ox) 3 ], 189,190 NPr 4 [Fe II Fe III -(ox) 3 ] (Pr ) n-C 3 H 7 ), 192 NBu 4 [Co II Fe III (ox) 3 ], 193 and NPe 4 [Mn II -Fe III (ox) 3 ] (Pe ) n-C 5 H 11 ) 194 and showed that these compounds exhibit similar behavioral characteristics of 2D structures. Antorrena et al 195 II Fe III (ox) 3 ], all of the complexes exhibited the magnetic phase transitions at low temperatures.…”

Mössbauer spectroscopic study of low-temperature spin structure and magnetic interactions in

“…From this observation, a magnetic-field-induced transition in this compound was postulated [7]. A heat capacity study of [8] detected the antiferromagnetic transition at 27.1 K associated with a small hump around 23 K. The estimated magnetic entropy confirmed the high-spin state of both Mn II and Fe III ions in this compound. The magnetic heat capacities above T N represented an S = 5/2 2D Heisenberg antiferromagnet with a honeycomb lattice structure with an intralayer exchange parameter J /k B = −3.3 K. The spin wave theory applied to the measured heat capacity data below T N revealed the existence of a very weak interlayer exchange interaction (J /k B = ±0.0014 K).…”

“…The {A[M II M III (ox) 3 ]} ∞ series of metal-assembled complexes with A = tetra n-alkyl/aryl ammonium/phosphonium cation, M II and M III = transition metal ions, and ox = oxalate ligand have been widely studied due to their illustrious magnetic properties [1][2][3][4][5][6][7][8][9][10]. The magnetic interactions observed in these complexes have originated from the super-exchange interaction between the two intralayer nearest-neighbor M II and M III metal ions mediated by oxalate ligands [1].…”

Dynamic magnetic behavior of the mixed spin (2, 5/2) Ising system with antiferromagnetic/antiferromagnetic interactions on a bilayer square lattice

“…[40] In brief, the molecular-based antiferromagnetic materials have interesting properties which need to be investgated. [41] Although a great amount is known about the equilibrium and nonequilibrium magnetic properties of various systems for the case of FM/FM and FM/AFM interactions on different bi-layer lattices, in comparison, only a few studies have been done on the equilibrium magnetic properties of various spin Ising systems for the case of AFM/AFM interactions on a bilayer Bethe lattice. [30][31][32] On the other hand, as far as we know, the dynamic magnetic properties of any bilayer system for the case of AFM/AFM interactions under a time varying (sinusoidal) magnetic field have not been studied.…”